A triggered ability triggers, but the player controlling the ability doesn’t demonstrate awareness of the trigger’s existence and/or forgets to announce its effect. If a triggered ability has been partially or incorrectly resolved, instead treat it as a Game Play Error — Game Rule Violation.A trigger is considered missed once the controller of the trigger has taken an action after the point at which a trigger should have resolved or, in the case of a trigger controlled by the non-active player, after that player has taken an action that indicates they have actively passed priority. Players may not cause triggered abilities to be missed by taking game actions or otherwise prematurely advancing the game. For example, if a player draws a card during his or her draw step without allowing the controller of a triggered ability that would trigger during that turn’s upkeep to resolve it, place that trigger on the stack at this point and issue no penalty.

ExamplesA. A player controls Braids, Cabal Minion. After he has declared attackers, he realizes that he has failed to sacrifice a permanent at the beginning of his upkeep.B. A player realizes that she forgot to remove the final counter from a suspended spell.C. A player forgets to pay the cumulative upkeep cost for a creature.D. A player controls Soul Warden and forgets to gain 1 life when a creature enters the battlefield under his opponent’s control.

Philosophy

Triggered abilities are common and invisible, so players should not be harshly penalized when forgetting about one. Players are expected to remember their own triggers; intentionally ignoring one is considered Cheating — Fraud. However, remembering triggers that benefit you is a skill. Therefore, players are not required to point out missed triggers that they do not control, though they may do so if they wish.The controller of the missed trigger only receives a Warning if the triggered ability is generally considered detrimental for the controlling player. The current game state is not a factor in determining this. Whether a Warning is issued or not does not affect how the trigger is handled, and Failure to Maintain Game State penalties are never issued to players who did not control the ability.Judges should not intervene in a missed trigger situation unless they intend to issue a Warning or have reason to suspect that the controller is intentionally missing his or her triggers.

Additional Remedy

If the trigger specifies a default action associated with a choice made by the controller of the trigger (usually "If you don't ..." or "... unless"), resolve the default action immediately without using the stack. If there are unresolved spells or abilities that are no longer legal as a result of this action, rewind the game to remove all such spells or abilities. Resulting triggers generated by the action still trigger and resolve as normal.If the duration of the effect generated by the trigger has already expired, or the trigger was missed more than a turn ago, instruct the players to continue playing.Otherwise, the opponent may choose to have the controller play the triggered ability. If they do, insert the forgotten ability at the appropriate place or on the bottom of the stack. No player may make choices involving objects that were not in the zone or zones referenced by the trigger when the ability should have triggered. For example, if the ability instructs a player to sacrifice a creature, that player can't sacrifice a creature that wasn't on the battlefield when the ability should have triggered.

DefinitionA triggered ability triggers, but the player controlling the ability doesn’t demonstrate awareness of the trigger’s existence the first time that it would affect the game in a visible fashion.

The point by which the player needs to demonstrate this awareness depends on the impact that the trigger would have on the game:

• A triggered ability that requires its controller to choose targets (other than 'target opponent'), modes, or other choices made when the ability is put onto the stack: The controller must announce those choices before they next pass priority.• A triggered ability that causes a change in the visible game state (including life totals) or requires a choice upon resolution: The controller must take the appropriate physical action or make it clear what the action taken or choice made is before taking any game actions (such as casting a sorcery spell or explicitlymoving to the next step or phase) that can be taken only after the triggered ability should have resolved. Note that casting an instant spell or activating an ability doesn’t mean a triggered ability has been forgotten, as it could still be on the stack.• A triggered ability that changes the rules of the game: The controller must prevent an opponent from taking any resulting illegal action.• A triggered ability that affects the game state in non-visible ways: The controller must take physical action or make it clear what the action is the first time the change has an effect on the visible game state.

Once any of the above obligations has been fulfilled, or the trigger has been otherwise acknowledged, further problems are treated as a Game Play Error — Game Rule Violation.

Triggered abilities that do nothing except create delayed triggered abilities automatically resolve without requiring acknowledgment. Awareness of the resulting delayed trigger must be demonstrated at the appropriate point. Triggered abilities that do nothing except create one or more copies of a spell or ability (such as storm or cipher) automatically resolve, but awareness of the resulting objects must be demonstrated using the same requirements as described above (even though the objects may not be triggered abilities).

Players may not cause triggered abilities controlled by an opponent to be missed by taking game actions or otherwise prematurely advancing the game. For example, if a player draws a card during his or her draw step without allowing an opponent to demonstrate awareness of a triggered ability, the controller still has an opportunity to fulfill the appropriate obligation by doing so at that point. The Out-of-Order Sequencing rules (MTR section 4.3) may also be applicable, especially as they relate to batches of actions or resolving items on the stack in an improper order.

If a triggered ability would have no impact on the game, it’s not an infraction to fail to demonstrate awareness of it. For example, if the effect of a triggered ability instructs its controller to sacrifice a creature, a player who controls no creatures isn’t required to demonstrate awareness of the ability.

ExamplesA. Knight of Infamy (a 2/1 creature with exalted) attacks alone. Its controller says “Take two.”B. A player forgets to remove the final time counter from a suspended spell and then draws a card during his draw step.C. A player casts Azorius Arrester, then forgets its triggered ability by not choosing a target for it. He realizes this only after casting another spell.D. A player forgets to exile the Angel token created by Geist of Saint Traft at end of combat. She realizes the error when declaring blockers during the next turn.

PhilosophyTriggered abilities are common and invisible, so players should not be harshly penalized when forgetting about one.

Players are expected to remember their own triggered abilities; intentionally ignoring one may be Unsporting Conduct — Cheating (unless the ability would have no impact on the game as described above). Even if an opponent is involved in the announcement or resolution of the ability, the controller is still responsible for ensuring the opponents make the appropriate choices and take the appropriate actions. Players are not required to point out triggered abilities that they do not control, though they may do so if they wish.

Triggered abilities are assumed to be remembered until otherwise indicated, and the impact on the game state may not be immediately apparent. The opponent’s benefit is in not having to point out triggered abilities, although this does not mean that they can cause triggers to be missed. If an opponent requires information about the precise timing of a triggered ability or needs details about a game object that may be affected by a resolved triggered ability, that player may need to acknowledge that ability’s existence before its controller does.

The controller of a missed triggered ability receives a Warning only if the triggered ability is usually considered detrimental for the controlling player. The current game state is not a factor in determining this, though symmetrical abilities (such as Howling Mine) may be considered usually detrimental or not depending on who is being affected.

Whether a Warning is issued or not does not affect any additional remedies that may be applicable. Failure to Maintain Game State penalties are never issued to players who did not control the ability.

Judges should not intervene in a missed trigger situation unless they intend to issue a Warning or have reason to suspect that the controller is intentionally missing his or her triggered abilities.

Additional RemedyIf the triggered ability specifies a default action associated with a choice made by the controller (usually "If you don't ..." or "... unless"), resolve it choosing the default option. If the triggered ability is a delayed triggered ability that changes the zone of an object, resolve it. For these two types of abilities, the opponent chooses whether to resolve the ability immediately or at the start of the next phase. These abilities do not expire and should be remedied no matter how much time has passed since they should have triggered.

If the triggered ability creates an effect whose duration has already expired or the ability was missed prior to the current phase in the previous player's turn, instruct the players to continue playing.

If the triggered ability isn’t covered by the previous two paragraphs, the opponent chooses whether the triggered ability is added to the stack. If it is, it’s inserted at the appropriate place on the stack if possible or on the bottom of the stack. No player may make choices involving objects that were not in the appropriate zone or zones when theability should have triggered. For example, if the ability instructs a player to sacrifice a creature, that player can't sacrifice a creature that wasn't on the battlefield when the ability should have triggered.